An apparatus has been proposed that displays a map where a road name as a character string is overlaid on a map image. For example, in an apparatus disclosed in JP-H9-101747, a name display frame for displaying a road name is preset within a map display frame for displaying a road map. When there is an intersection between the name display frame and a road displayed on the map display frame, a corresponding road name is displayed on the intersection.
In such a conventional apparatus, as the number of characters in a character string overlaid on a map image is larger, visibilities of the map image and the character string become worse.